From the lockfile_create manual page (http://linux.die.net/man/3/lockfile_create) you can confirm the answer to your questions is yes: "One, it just creates a lockfile- it doesn't know which file you are actually trying to lock!"

Many thanks for the patch! As far as I can see it is correct: implements mbox locking in the recommended order, also giving priority to lockf (fnctl) over flock on systems which have both (like Debian systems).

Are you planning to do a new release soon?

Just asking to see if it's worth to port the patch to current Debian package or is simply better to wait a few days for the new release.

(though I don't recommend to include beta versions in official distributionrepository, since they tend to contain incomplete implementation)

In Debian betas are uploaded to sid (unstable) in order to gain wider exposure and detect possible problems. They also migrate to the testing distribution according to the usual rules (time enough, no RC bugs). At the time of freeze it may happen a beta is the one in testing, therefore it may be released in the stable distribution.

By your comment I'm not sure if you would prefer another kind of management or not.

It's possible to upload betas just to experimental, and only final versions to unstable to ensure only final versions are distributed in stable. But this has also important drawbacks.

Just let me know. You can just mail me privately if you prefer or even on the mailing list if you want a public discussion.